Armrest Structure of a Foldable Chair

ABSTRACT

The present invention provides an armrest structure of a foldable chair, including an armrest cushion and a frame. The armrest cushion includes a mounting plate and a cushion pad. The mounting plate is fixedly mounted in the cushion pad via the injection molding process. The cushion pad has a first end for connecting a curved portion and a second end. The mounting plate has a first end for connecting a curved portion and a second end. The curved portion of the mounting plate is located inside the curved portion of the cushion pad, so the curved portion of the cushion pad is strengthened. The frame is disposed at a bottom of the armrest cushion. The structure of the cushion pad is strengthened by the mounting plate. In addition, the wrist portion of the user may be properly supported by the curved portions of the cushion pad and the mounting pad.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates generally to an armrest structure, more particularly, relates to an armrest structure of a foldable chair with a reinforced armrest cushion. The reinforced structure of the armrest cushion is provided by forming a mounting plate inside a cushion pad with injection molding process.

2. The Prior Arts

An armrest structure is provided on both sides of a chair, so a user may rest his/her hands on the armrest structure for relief and relaxation purposes.

FIG. 1a is a perspective and exploded view of a detachable armrest of a foldable chair from Taiwan Patent No. M362640, which was designed by the inventor of the present invention. As shown in FIG. 1a , a conventional armrest structure includes a cushion pad 91 and a frame 92. The cushion pad 91 is made from an elastic material and is disposed on the frame 92. The frame 92 is mounted on a side of the foldable chair 90. When a user sits on such a foldable chair, he/her may rest his/her hands against the cushion pads 91 of the armrest structure.

As can be seen from FIG. 1a , the conventional armrest structure is horizontally displaced, and the two ends of such an armrest structure are both flat and straight. Hence, when the hand of a user is rested against the armrest structure, the wrist portion of the user may only be placed thereon in a flat manner, or, the wrist portion of the user may only be dangled therefrom. Such a conventional armrest structure is not ergonomic and may cause discomfort.

FIG. 1b is a side sectional view of the conventional armrest structure. As shown in FIG. 1b , in order to enhance the supporting strength of the cushion pad 91, a groove 93 is provided on a side of the frame 92 that is located at the bottom of the cushion pad 91. However, when the foldable chair 91 is used in an outdoor occasion, it is often exposed to rainfall and rainwater may accumulate in the groove 93. The accumulated rainwater may further cause the groove to corrode. In addition, sand and dust are also easily accumulated in the groove 93, thus causing inconvenience in the cleaning process. Hence, there is a need to improve the disadvantages described above.

SUMMARY OF THE INVENTION

Due to the foregoing reasons, a primary objective of the present invention is to provide an armrest structure of a foldable chair. A mounting plate is formed inside a cushion pad of the foldable chair with injection molding process so as to enhance the strength of the cushion pad.

Another objective of the present invention is to provide an armrest structure of a foldable chair that could support the wrist portion of the user. In such a way, the degree of comfort in using the foldable chair is enhanced, and the armrest structure is also more ergonomic.

Yet another objective of the present invention is to provide an armrest structure of a foldable chair that has a simple structure to facilitate convenience in cleaning and also to decrease the time needed for cleaning.

For achieving the foregoing objectives, the present invention provides an armrest structure of a foldable chair, comprising an armrest cushion and a frame. The armrest cushion comprises a mounting plate and a cushion pad. The mounting plate is fixedly provided inside the cushion pad via the injection molding process. The cushion pad has a first end and a second end. The first end of the cushion pad is connected with a curved portion of the cushion pad. The mounting plate includes a first end and a second end. The first end of the mounting plate is connected with a curved portion of the mounting plate and the curved portion of the mounting plate is located inside the curved portion of the cushion pad. The frame is disposed at a bottom of the armrest cushion.

In one embodiment of the present invention, the armrest structure of the present invention further comprises at least one screw and the mounting plate further comprising at least one tapped hole. The frame comprises a joining plate, a rod body, a supporting rod and a joining portion. The joining plate has at least one positioning hole. The at least one screw is configured to sequentially pass through the at least one positioning hole and the at least one tapped hole so that the joining plate is fixed with the armrest cushion. The rod body is connected to the joining plate with a tilted angle therebetween. Two ends of the supporting rod are respectively connected to the joining plate and the rod body, and the joining portion is provided at least one side of the rod body.

Herein, a top surface of the mounting plate further includes at least one protrusion. The at least one tapped hole is formed through the at least one protrusion.

Herein, a bottom portion of the cushion pad comprises a recess. An inner contour of the recess is configured to match an outer contour of the joining plate. The joining plate is disposed inside the recess such that a bottom portion of the joining plate is aligned with the bottom portion of the cushion pad.

In one embodiment of the present invention, the armrest structure of the present invention further comprises two of the screws. The mounting plate comprises two of the tapped holes. The joining plate comprises two of the positioning holes. The screws are configured to sequentially pass through the positioning holes and the tapped holes so as to fix the joining plate with the armrest cushion.

In one embodiment of the present invention, when viewed from a side of the armrest cushion, the curved portions of the cushion pad and the mounting plate are shaped as a quarter circle.

In one embodiment of the present invention, an end of the curved portion of the mounting plate is in proximity to an end of the curved portion of the cushion pad.

In one embodiment of the present invention, the mounting plate further comprises at least one rib. The at least one rib is protruded from a top surface of the mounting plate. At least one groove is formed on a bottom surface of the mounting plate at a location corresponding to the at least one rib. The at least one rib and the at least one groove are configured to extend in a length direction of the mounting plate.

In one embodiment of the present invention, the mounting plate further comprises at least one tapped hole. Two of the ribs are respectively configured to extend through the two sides of the at least one tapped hole.

Herein, the at least one rib is configured to extend from the second end of the mounting plate to an end of the curved portion of the mounting plate, which is connected to the first end of the mounting plate.

In short, by fixedly mounting the mounting plate inside the cushion pad via the injection molding process, the strength of the cushion pad is enhanced in the present invention. In addition, the mounting plate is also strengthened with the grooves and ribs formed thereon.

Further, when a user sits on the foldable chair with the armrest structure of the present invention, the wrist portion of the user may be properly supported by the curved portion of the cushion pad. In such a way, the degree of comfort in sitting on the chair is enhanced, and the armrest structure is more ergonomic.

Moreover, by forming a recess at the bottom portion of the cushion pad such that an inner contour of the recess matches an outer contour of the joining plate, the bottom portion of the joining plate is able to align with the bottom portion of the cushion pad when the joining plate is disposed inside the recess. The problem of water accumulation, corrosion or sand and dust accumulation may be simply eliminated with such a simple structure.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be apparent to those skilled in the art by reading the following detailed description of a preferred embodiment thereof, with reference to the attached drawings, in which:

FIG. 1a is a perspective and exploded view of a conventional and detachable armrest structure of a foldable chair;

FIG. 1b is a cross-sectional side view illustrating the conventional armrest structure.

FIG. 2 is a perspective view of an armrest structure of a foldable chair according to a preferred embodiment of the present invention;

FIG. 3 is a perspective and exploded view illustrating the armrest structure of the foldable chair according to the preferred embodiment of the present invention;

FIG. 4 is a perspective view illustrating a mounting plate of the armrest structure of the foldable chair according to the preferred embodiment of the present invention;

FIG. 5 is a cross-sectional side view illustrating the armrest structure of the foldable chair according to the preferred embodiment of the present invention;

FIG. 6 is another perspective and exploded view illustrating the armrest structure of the foldable chair according to the preferred embodiment of the present invention;

FIG. 7 is an cross-sectional perspective view illustrating the armrest structure of the foldable chair according to the preferred embodiment of the present invention; and

FIGS. 8 and 9 are schematic views illustrating the assembled armrest structure of the foldable chair according to the preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

FIG. 2 is a perspective view of an armrest structure of a foldable chair according to a preferred embodiment of the present invention, and FIG. 3 is a perspective and exploded view of the armrest structure according to the preferred embodiment of the present invention. As shown in FIGS. 2 and 3, the armrest structure of the present invention comprises: an armrest cushion 10 and a frame 50. Detailed description of each component will be provided in the following paragraphs.

The armrest cushion 10 includes a cushion pad 30 and a mounting plate 20. The cushion pad 30 is made of an elastic material and includes a first end 31 and a second end 32. The first end 31 is connected to a curved portion 33 of the cushion pad 30. The mounting plate 20 is fixedly provided inside the cushion pad 30 via the injection molding process. The mounting plate 20 has a first end 21 and a second end 22. The first end 21 is connected to a curved portion 23 of the mounting plate 20. Herein, the curved portion 23 is located inside the curved portion 33.

FIG. 4 is a perspective view illustrating the mounting plate 20 of the armrest structure according to the preferred embodiment of the present invention. In the preferred embodiment of the present invention, the mounting plate 20 further includes two protrusions 24. The two protrusions 24 are formed on a top surface of the mounting plate 20 via the broaching process. Each of the protrusions 24 has a tapped hole 26.

Herein, in order to strengthen the mounting plate 20, at least one groove 27 (shown in FIG. 7) is formed on a bottom surface of the mounting plate 20 by pressing the bottom surface of the mounting plate 20 toward the top surface of the mounting plate 20. At least one rib 25 is provided at a top surface of the mounting plate at a corresponding location. In the preferred embodiment of the present invention, the mounting plate has two ribs 25 and two grooves 27. The two ribs 25 and the two grooves 27 are extended along a length direction of the mounting plate 20, respectively. More particularly, the two ribs 25 are configured to extend from the second end 22 to an end of the curved portion 24 of the mounting plate 20, which is connected with the first end 21. Preferably, the two ribs 25 and the two grooves 27 are provided on two sides of the protrusions 24.

The frame 50 is disposed at a bottom of the armrest cushion 10. More particularly, the armrest structure further includes two screws 60. The frame 50 further includes a joining plate 51, a rod body 52, a supporting rod 53 and a joining portion 54. The joining plate 51 includes two positioning holes 511. The two screws 60 are configured to sequentially pass through the two positioning holes 511 and are fixedly mounted to the two tapped holes 26 of the mounting plate 20 inside the cushion pad 30, such that the joining plate 51 is fixed with the armrest cushion 10. The rod body 52 is connected to the joining plate 51 with a tilted angle therebetween. Two ends of the supporting rod 53 are respectively connected to the joining plate 51 and the rod body 52. The joining portion 54 is provided at at least one side of the rod body 52. In the preferred embodiment of the present invention, the rod body 52, the supporting rod 53, the joining plate 51 and the joining portion 54 are integratedly formed via the welding process.

FIG. 5 is a cross-sectional side view illustrating the armrest structure according to the preferred embodiment of the present invention. As shown in FIG. 5, In the preferred embodiment of the present invention, when viewed from a side of the armrest cushion 10, the curved portions 33 and 23 of the cushion pad 30 and the mounting plate 20 are shaped as a quarter circle. However, the curvature of the curved portions 33 and 23 are not limited thereto and may be adjusted according to actual design needs. Hence, when the hand of the user is rested against the armrest structure, the wrist portion of the user is properly supported by the curved portion 33. The degree of comfort of the chair is thereby enhanced, and the armrest structure is also more ergonomic.

In the preferred embodiment of the present invention, an end of the curved portion 23 of the mounting plate 20 is in proximity to an end of the curved portion 33 of the cushion pad 30.

FIG. 6 is another perspective and exploded view illustrating the armrest structure according to the preferred embodiment of the present invention. As shown in FIG. 6, in the preferred embodiment of the present invention, a recess 34 is provided at a bottom portion of the cushion pad 30. An inner contour of the recess 34 is configured to match an outer contour of the joining plate 51 such that the joining plate may be disposed inside the recess 34. In the preferred embodiment of the present invention, the depth of the recess 34 is the same as the height of the joining plate 51. Hence, when the joining plate 51 is disposed inside the recess 34, a bottom portion of the joining plate 51 is aligned with the bottom portion of the cushion pad 30.

FIGS. 8 and 9 are schematic view illustrating the assembled armrest structure according to the preferred embodiment of the present invention. As shown in FIGS. 8 and 9, at least one connecting portion 81 is provided on each side of the chair 80. The structure of the connecting portion 81 matches the structure of the joining portion 54 so that the connecting portions may be assembled with the joining portions 54.

More particularly, in the preferred embodiment of the present invention, the connecting portion 81 includes a positioning hole 82. The positioning hole 82 includes a large hole 83 and a small hole 84. The large hole 83 is formed on an end of the small hole 54. As shown in FIG. 3, the joining portion 54 includes a protrusion 541. The protrusion 541 includes a head portion 542. The outer contour of the head portion 542 is smaller than the large hole 83 and is larger than the small hole 84. The outer contour of the protrusion 541 is smaller than the small hole 84.

During the assembling process, the joining portion 54 of the frame of the present invention is first pointed at the connecting portion 81 of the chair 80. Then, the head portion 542 of the protrusion 541 of the joining portion 54 is inserted in to the large hole 83 and is further moved toward the small hole 84. Since the size of the head portion 542 is larger than the small hole 84, the protrusion 541 may be engaged in the engagement slot 82. In such a way, the armrest structure of the present invention may be assembled on both sides of the chair 80.

In the preferred embodiment of the present invention, the frame 50 has two of the joining portions 54. The number of the joining portions 54 corresponds to the number of the connecting portions 81. However, the number of the joining portions 54 of the frame 50 is not limited thereto and may be adjusted according to the actual number of the connecting portions 81 of the chair 80. In the preferred embodiment of the present invention, two of the joining portions 54 are provided on the same side of the frame 50. Nevertheless, the number and location of the joining portions 54 are not limited thereto. The number of the joining portions 54 may be increased according to design needs and may be provided on both sides of the frame 50.

In short, by fixedly mounting the mounting plate 20 inside the cushion pad 30 via the injection molding process, the strength of the cushion pad 10 is enhanced in the present invention. In addition, the mounting plate 20 is also strengthened with the grooves 27 and ribs 25 formed thereon.

Further, when a user rest his/her hand against the armrest cushion 10 of the present invention, the wrist portion of the user may be properly supported by the curved portion 33 of the cushion pad 30 and the curved portion 23 of the mounting plate 23. In such a way, the degree of comfort in sitting on the chair is enhanced, and the armrest structure is more ergonomic.

Moreover, by forming a recess 34 at the bottom portion of the cushion pad 30 such that an inner contour of the recess 34 matches an outer contour of the joining plate 51, the bottom portion of the joining plate 51 is able to align with the bottom portion of the cushion pad 30 when the joining plate 51 is disposed inside the recess 34. The problem of water accumulation, corrosion or sand and dust accumulation may be simply eliminated with such a simple structure.

Although the present invention has been described with reference to the preferred embodiments thereof, it is apparent to those skilled in the art that a variety of modifications and changes may be made without departing from the scope of the present invention which is intended to be defined by the appended claims. 

What is claimed is:
 1. An armrest structure of a foldable chair, comprising: an armrest cushion having a mounting plate and a cushion pad, wherein the mounting plate is fixedly provided inside the cushion pad via the injection molding process, the cushion pad has a first end and a second end, the first end of the cushion pad is connected with a curved portion of the cushion pad, the mounting plate includes a first end and a second end, the first end of the mounting plate is connected with a curved portion of the mounting plate, wherein the curved portion of the mounting plate is located inside the curved portion of the cushion pad; and a frame disposed at a bottom of the armrest cushion.
 2. The armrest structure according to claim 1, further comprising at least one screw and the mounting plate further comprising at least one tapped hole, wherein the frame comprises a joining plate, a rod body, a supporting rod and a joining portion, the joining plate has at least one positioning hole, the at least one screw is configured to sequentially pass through the at least one positioning hole and the at least one tapped hole so that the joining plate is fixed with the armrest cushion, wherein the rod body is connected to the joining plate with a tilted angle therebetween, two ends of the supporting rod are respectively connected to the joining plate and the rod body, and the joining portion is provided at at least one side of the rod body.
 3. The armrest structure according to claim 2, wherein a top surface of the mounting plate further includes at least one protrusion, the at least one tapped hole is formed through the at least one protrusion.
 4. The armrest structure according to claim 2, wherein a bottom portion of the cushion pad comprises a recess, an inner contour of the recess is configured to match an outer contour of the joining plate, the joining plate is disposed inside the recess such that a bottom portion of the joining plate is aligned with the bottom portion of the cushion pad.
 5. The armrest structure according to claim 2, further comprising two of the screws, wherein the mounting plate comprises two of the tapped holes, the joining plate comprises two of the positioning holes, the screws are configured to sequentially pass through the positioning holes and the tapped holes so as to fix the joining plate with the armrest cushion.
 6. The armrest structure according to claim 1, wherein when viewed from a side of the armrest cushion, the curved portions of the cushion pad and the mounting plate are shaped as a quarter circle.
 7. The armrest structure according to claim 1, wherein an end of the curved portion of the mounting plate is in proximity to an end of the curved portion of the cushion pad.
 8. The armrest structure according to claim 1, wherein the mounting plate further comprises at least one rib.
 9. The armrest structure according to claim 8, wherein the at least one rib is protruded from a top surface of the mounting plate, at least one groove is formed on a bottom surface of the mounting plate at a location corresponding to the at least one rib, the at least one rib and the at least one groove are configured to extend in a length direction of the mounting plate.
 10. The armrest structure according to claim 8, wherein the mounting plate further comprises at least one tapped hole, two of the ribs are respectively configured to extend through the two sides of the at least one tapped hole.
 11. The armrest structure according to claim 8, wherein, the at least one rib is configured to extend from the second end of the mounting plate to an end of the curved portion of the mounting plate, which is connected to the first end of the mounting plate. 